Fix typo in billing requests documentation

Add missing ) in copilot-requests.md

Author: Cubox

content/copilot/concepts/billing/copilot-requests.md

@@ -48,7 +48,7 @@ The following {% data variables.product.prodname_copilot_short %} features can u
 
 If you use **{% data variables.copilot.copilot_free_short %}**, your plan comes with up to 2,000 code completion requests and up to 50 premium requests per month. All chat interactions count as premium requests.
 
-If you're on a **paid plan**, you get unlimited code completions and unlimited chat interactions using the included models ({% data variables.copilot.copilot_gpt_41 %} and {% data variables.copilot.copilot_gpt_4o %}. Rate limiting is in place to accommodate for high demand. See [AUTOTITLE](/copilot/concepts/rate-limits).
+If you're on a **paid plan**, you get unlimited code completions and unlimited chat interactions using the included models ({% data variables.copilot.copilot_gpt_41 %} and {% data variables.copilot.copilot_gpt_4o %}). Rate limiting is in place to accommodate for high demand. See [AUTOTITLE](/copilot/concepts/rate-limits).
 
 Paid plans also receive a monthly allowance of premium requests, which can be used for advanced chat interactions, code completions using premium models, and other premium features. For an overview of the amount of premium requests included in each plan, see [AUTOTITLE](/copilot/about-github-copilot/subscription-plans-for-github-copilot#comparing-copilot-plans).